1-Definition of substance-
Anything that has a density, occupies space, and is able to be felt by one or more of the senses. Substance (Matter) is called.
For example – air and water; hydrogen and oxygen; sugar and sand; silver and steel; iron and wood; ice and wine; milk and oil; carbon dioxide and steam; carbon and sulfur; Rocks and minerals etc. These are different types of matter that have mass, volume and occupy space. They exist in the form of solid, liquid, gas and plasma.
There are three types of physical classification.
1. solid solid
, solid : Substance The physical state of matter whose shape and volume are both fixed is called a solid. For example, an iron rod, a wooden chair, a piece of ice
2.liquid – There was a lot of matter whose shape is uncertain and volume is fixed, it is called liquid.
Examples like water, alcohol, kerosene etc.
3.Gas gas The physical state of the market in which both its shape and volume are uncertain is called a gas, e.g. air, oxygen, matter.
2-Particles of matter attract each other –
A force acts between the particles of matter which holds the particles of matter together. The strength of this force of attraction between the particles of matter is different in different substances.
This force of attraction between the particles of some substances is very high and this force of attraction between the particles of some substances is very less.
Matter becomes hard or soft only because of the strong or weak force of attraction between their particles.
For example, iron is very hard, whereas a piece of chalk is not hard. It takes a lot of force to break a piece of iron, whereas a piece of chalk can be broken easily. This is because the force of attraction between the particles of iron is very strong and the force of attraction between the particles of chalk is very weak.
3-How small are these particles of matter?
These particles of matter are so tiny that they cannot be seen with the naked eye.
When a few drops of Dettol are added to a glass of water, it turns the entire water into a milky color, indicating that the substance is made up of very fine particles.
4-Physical nature of matter –
All matter is made up of tiny particles. These particles are so small that they cannot be seen with the naked eye. The truth that matter is made up of tiny particles can be tested by some small activity, such as when salt or sugar is dissolved in water, they dissolve in water.
This activity shows that matter is made up of small particles.
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